Method of making asbestos cement shingles



Jan. 12, 1943, A. F. DE VAULT METHOD OF MAKING ASBESTOS CEMENT SHINGLESFiled April 50, 1941 1 I I I 1 1 I 1 I I I u I l m/ m u v w e 1D 7 w mBY, 2 y ATTQRNEYZ Patented Jan. 12, 1943 Aylett F. De Vault, Nichols,com, assignor to Tilo Roofing Company, Inc., Stratford, Conn., a

corporation of Delaware Application April 30, 1941, Serial No, 391,025

Claims.

- This invention relates to the art of making earthen or cement shinglesand the like, and has for an object the provision of improvements inthis art.

One of the objects of the invention is to produce a shingle in which theembossing or grain is clearly brought out by a two-tone effect and madefully perceptible even at a distance. Another object is to produceselected color effects with the emphasized grain efiect. Another objectis to produce grain and color eflects which are as permanent incharacter as the material on which they are produced. And yet anotherobject is to produce the desired effects in a simple and inexpensivemanner.

The invention is particularly applicable to the manufacture ofcement-asbestos shingles and will be described in this connection; butit is to be understood that it applies as well to siding, blocks andother articles made of the same materials,

and also to articles made of other moldable materials in a'similar way.

One application of the invention is illustrated in the accompanyingdrawing, wherein:

Fig. 1 is a surface view of a shingle made according to the invention;

Fig. 2 is an end view of the lower end of Fig. 1; and

Fig. 3 is an enlarged view of a section through the shingle.

A popular type of outer covering for buildings is. a rock-likecement-asbestos shingle which is formed with a grain to imitate aweather-worn wood shingle. However, when such a shingle is made in thenatural color of the material the eflect of the graining is largelylost,.particularly at a distance. When the shingle is made in colors theefiect is still lost if, as is usual, the color pigment is uniformthroughout the entire body or over the entire surface of the shingle.

color or shade the surface coating layer will be another color or shade.

Cement-asbestos shingles may be made, according to one common process,by forming a sheet from a slurry ofasbestos fiber and cement -on thecylinder of a machine by what is known 'as the Hatschek" process. Thedetails of this or. other sheet-forming processes are unimportanthere,it being only necessary to note that, as comsembling rolled out piedough until the cement .the sheets. The stack of plates and alternatingAccording to the present invention, a dlstinctive coating is applied tothe shingles andthis is done in such a manner as to be discontinuous atthe proper places to bring out the graining by contrast between thecoated portions and the exposed uncoated portions. The coating materialis present in the valleys but is largely absent on the crests; and onthe gentler sloping portions monly practiced, there are produced limpsheets of any desired thickness and size, for example, about thick andabout 25" x 25" in extent. These sheets remain in a limp conditionrebegins to harden, which is a matter of three or four hours. Since thesurface begins to harden first, a skin is formed on each side and theinterior attains a state .of increased coherency suflicient to preventpulling apart or splitting when the plates are separated after thepressing operation, next to be described.

Continuing with the common process for making grained shingles, thedrying but still impressionable sheets, say after about three hours (theperiod varying considerably with atmospheric and other conditions), areplaced in alternation between embossed plates of a plastic material suchas Bakelite. The plates may be made of cloth and a plastic, of hardrubber, bronze, aluminum or other suitable materials. Preferably thegrained plates are embossed on both sides and alternate with smoothmetal plates between sheets is placed in a press and subjected to a highpressure of say 2500 or 3000 lbs. per square inch. This presses outconsiderable water and causes the sheets to take the embossing orgraining of the plates. The sheets are then removed from the plates andplaced in stacks to cure or set for at least ten days in a moistcondition. Certain manufacturers'hasten the cure by placing them insteam chambers and in other ways known in the curing of cements. Aftercuring and hardening, the sheets are cut into the exact sizes desiredfor finished shingles.

According to one known process, if colored shingles are desired, thecolor pigment is added to the entire amount of slurry from which thebody of the shingles or the outer layer is formed. This produces amonotone over the entire surface and this single "color alone does notbring out the graining, as desired.

According to the present invention, the sheets are formed from the basicmaterial, asbestosf 7 grainlng, they are coated with a material ofanother color or shade. They may, for example, be sprayed with a slurryof cement containing the desired color pigment. Or a dry film ofpigmented cement may be applied which is moistened after application asby the water left in the shingle or by a dampening for the purpose. Or acoating layer may be flowed on and the excess removed in a convenientmanner as by an I air blast. The coating produced is very thin andadheres to the sheets. Eventually it becomes integral with the sheets,particularly when of a like nature. The coating is applied just beforethe sheets are assembled with the embossed plates .for pressing. If thecoating is thus. applied to partly cured sheets and is still dampwhen'the graining is embossed on the sheets, the coating layer will bebroken at the grain crests to expose the diflerently colored basematerial and thus bring the graining into relief. If the pigmentedslurry is applied earlier and becomes drier, it

' will adhere to the base material uniformly throughout its entiresurface and will not break.

up'or' be removed at places to expose the base material and bring thegraining into relief, as

' desired. If the sheets are coated in the usual waysafter the grainimpressing operation, the eflect is artificial like that of commonpainted surface coatings.

Inthe drawing, the cement-asbestos base is represented by the numeralIII, the grain crests by II and the valleys by the numeral l2. Thecoating is shown" greatly exaggerated in thickness tion that as themolds press into the sheet to form the grain, there is a heavy outflowor water from the embossed faces. The crests, and particulariy thegentler sloping surfaces near the crests, give the appearance of waterflow havin washed off part of the coating layer. In part too the effectmay be due. to a stretching of the tenuous base surface in changing froma plane surface to a grained surface. The length of the surface acrossthe grain may be doubled in this change. The coating layer, beingunhardened and not yet firmly attached to the base surface, will breakand the base surface will stretch to form the exposed crests free of thecoating layer.

While certain theories of the creation of the effect have beendiscussed, it is to be understood that the invention does not dependupon these or any other theories, it being suflicient to know that theprocedure disclosed will produce the desired article.

- procedure by which the new article may be proin Fig. 3 and isrepresented by the-numeral l3.

Principally, the coating is left in the valleys l2 and is largely absenton the crests l l. The gently sloping areas is are partlycoated andpartly exposed. They are mottled or rivuleted to have the appearance ofseashore mud flats with streams as-seen from an airplane.

, Although the coating is very thin it will last for the life of theshingle because it is of like The effect may be produced by theapplication has become tenuous, together'with a suitable treatment toremove the still 'unhardened layer from the crests. When the effect -'isproduced in the pressing operation, it may be due to the escape of waterfrom the crests, that is, in the valleys of the mold, after the crestsof the mold have firmly engaged the other portions of the layer. Thistheory is supported by the observa- .of the fresh coating layer to'abody surface which 'duced, Therefore, the invention is not to be limitedexcept by the prior art and the scope a the subjoined c1aims.

asbestos-cement shingles: and the like, which comprises, forming a limpwetshet from ashes- 1 tos-cement slurry, curing the sheet until ithas.

attained appreciable cohesionv and surface tenacity, applying to thesurface of the sheet-a v pigmented cement slurry to form a very' .thin

coating, and embossing the sheet while the co at ing is still damp toexpose the crests of the em,- bossed grains through the coating andleave the coating in the valleys.

2. The method of,making a molded earthen,

article with a two-to e relief effect which cornprises, forming a hoplying a surface coating after the-body has at tained appreciablecohesion and surface tenacity, and embossing said body under highpressure while the coating is damp to expose the crests .of the embossedsurface and leave the coating in the valleys.

3. The method of making two-tone embossed molded earthen articles whichcomprises, forming a cement-bonded body,.applying a thin pig-- Q mentedcement surface coating after the body has attained appreciable cohesionand surface tenacity'but while still soft, and embossing-said 4. Themethod of making 'two-tone grained asbestos-cement shingles and the likewhich i comprises applying an even coating of a -plgmented cement slurryat a stage after the base sheet has attainedappreciable cohesion andsurface tenacity, forming grains on a surface of the sheet, and removingthe coating on the crests of the grains at the tops and for a shortdistance down on thesides while the coating is stillsoft.

5. The method asset forth in claim 4 further characterized by thefactthat the coating is re-. moved from the crests of the. grains in apressing operation which causes water to flow out of the grainedsurface. v

' AYIETI F. DE VAULT.

Moreover, this may not be the only 7 ofcement and fiber, ap-

